Underfloor heating problem

[Baz178]

Yes everything his fine upstairs work how it should.
Upstairs one

 

[Baz178]

So, just to be clear in my own mind, the U/stairs will run on its own, is that correct?.

If so can you take two sets of readings as requested
I am trying to see if the u/stairs heat demand is the same or more (when running on its own) than the d/stairs

 

[Baz178]

Downstairs one

 

[Johntheo5]

Thanks, but can you also give me the total of the U/stairs flowmeter flow rates as well as that manifold temperature, I can then calculate the UFH demand with the U/stairs running on its own.

Also, if available, the boiler flow temperature and boiler return temperature.

 

[Baz178]

Thanks, but can you also give me the total of the U/stairs flowmeter flow rates as well as that manifold temperature, I can then calculate the UFH demand with the U/stairs running on its own.

Also, if available, the boiler flow temperature and boiler return temperature.

How do I get the boiler temp and return temp ?

 

[Johntheo5]

No idea I'm afraid, not familiar with that boiler, can you just take the UFH readings?.

 

[Baz178]

What do you need on the UFH reading ? Where can I find that ?

 

[Johntheo5]

Have you got UFH upstairs or is it rads??, IF UFH then you will have a manifold like the D/stairs with loops which have flow meters, read them and read the manifold flow temperature.

 

[Rodders53]

My oil fired system has three motorised valves... one for Hot Water tank, one for the UFH down and a third for the Radiators upstairs.
This system may have similar valves, somewhere for the two heating zones, at least?

My suspicions here are that the UFH is calling for heat (UFH control box 'boiler on'), motoring the valve open but the end microswitch isn't making... and hence not firing the boiler to heat water. When upstairs calls for heat the up valve motors open and the microswitch in that up valve fires the boiler to heat both circuits.

 

[Johntheo5]

Something like that one would think but the boiler is apparently being asked to start when d/stairs UFH only requested, post #3, so a bit strange.

 

[Baz178]

My oil fired system has three motorised valves... one for Hot Water tank, one for the UFH down and a third for the Radiators upstairs.
This system may have similar valves, somewhere for the two heating zones, at least?

My suspicions here are that the UFH is calling for heat (UFH control box 'boiler on'), motoring the valve open but the end microswitch isn't making... and hence not firing the boiler to heat water. When upstairs calls for heat the up valve motors open and the microswitch in that up valve fires the boiler to heat both circuits.

Yes that’s what’s happening so how do I fix ?

 

[Rodders53]

Yes that’s what’s happening so how do I fix ?

Are you sure. Your post #3 possibly suggested the boiler ran with UFH call only see post #40... if it did not and was just the lamp on the manifold control box, then...

Fix the faulty motorised valve issue.

It will depend on the exact nature of the fault:
The valve may not be opening fully due to a mechanical issue and therefore not operating the microswitch. A new valve and actuator will fix that.
If it opens fully and the switch doesn't mechanically operate, something is broken or misaligned inside the actuator. It may be fixable if dismantled and reassembled correctly; or just replace the actuator head. (Or a complete valve and actuator if head is not removable).
It may be a broken wire in the head, or a faulty microswitch contact. It may be fixable by dismantling, or not.

 

[snb1]

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